: Quick question about using the rolling bevel method. When you place a strip
: on the kayak, do you bevel the top edge so that it is basically
: horizontal, and then put the next piece in place and match the bevel to
: that... or do you just put the piece on, leaving the top edge with a 90
: degree corner, and do all of the beveling on the bottom of the next strip?
: I was reading through this thread (
: http://www.kayakforum.com/cgi-bin/Building/index.cgi?review=133617 ) and
: came across this image which shows leaving the 90 degree angle on the top
: of the strip and only beveling the bottom edge. I guess it would be easier
: this way but I was just checking to see what is definitely the way to go.

I'm assuming the image you saw was one of my earlier illustrations. So I guess you might as well get MY comments on it Not sure if that means getting thins straight from the horses mouth, or getting info from the other end of the horse --but here goes.

Beveling both edges of the strip will give a better fit between them, but in practice it is much harder to do. In barrel making all the barrel staves are beveled to the same angle. If you were making a barrel with 36 staves each edge would have a 5 degree angle cut on it. When you put two adjacent pieces together they will meet at a 10 degree angle. with 36 pieces you get 360 degrees, or the complete "circle" of the barrel.

That is great for a regular, even structure. But with a kayak there are places on the boat where the strips meet squarely -- flat areas on the deck, for example. There are also areas where the strips form a large radius curve ( the deck) and there are also places where the boat's hull makes a very great bend over a very few strips. This would be (for example) in the area where the bottom of the boat changes into the sides. Since the strips might twist along their length, it is possible that one strip might be horizontal in the middle of the boat, but be twisted vertical by the ends of the boat. With wide canoes you may see this more than with kayaks--but it will happen.

When you have those few strips making such a tight turn (say 90 degrees over the width of 4 strips) you have 8 edges involved, and that 90 degrees is split over the 8 edges. Each one gets beveled a bit over 11 degrees.

Someone suggested cutting an 11 degree bevel one all edges. I think that would be a bit strong for a canoe, but might be great for a narrower kayak. If I wanted to cut all my strips, and mill them with bevels on both edges, I'd probably go with about a 5 degree angle on the edges (for the people trying to figure this out with their geometry books, that would probably mean making the cross section of a strip look like a trapezoid with the two base angles at 85 degrees, and the two upper angles at 95 degrees.)

The nice thing about prebeveled strips is that in the flatter areas of the boat where you don't need a bevel at all, just flip every other strip and they nest together nicely, with a slightly larger gluing surface.

When beveling by hand, it is a pain to work on the strip which has been installed (the plane keeps running into the building forms), so you work on the strip which has not yet been installed.

One person suggested another technique which I haven't tried, but it sounds workable: Temporarily mount the new strip in place. Use a circular saw to cut along the small gap between the edges of the installed strip and the new one. The kerf of the saw blade would effectively bevel both strips the proper amount. After making the cut you would jsut slide the new strip over to fill the gap created by the kerf of the sawblade. Personally, I get a little sloppy when trying to follow a line with a circular saw, so I'm not about to make this my regular practice-- but if you have better coordination than I do, or you have a couple of strips that are REALLY hard to fit, this would do the job.

Hope this helps.

PGJ